Texas Instruments CY74FCT2245ATSOC

Overview

CY74FCT2245ATSOC from Texas Instruments is an 8-bit noninverting bidirectional transceiver with 3-state outputs, designed for bus interface applications in industrial and embedded systems. It features 4.6 ns maximum propagation delay, ±15 mA output drive capability, 25-Ω integrated series output resistors, Ioff partial-power-down support, and TTL-compatible input/output logic levels.

For engineers reviewing the CY74FCT2245ATSOC datasheet, CY74FCT2245ATSOC pinout, CY74FCT2245ATSOC application, or CY74FCT2245ATSOC equivalent, key selection criteria include bidirectional bus isolation timing, 3-state control sequencing (OE/T/R), thermal performance in SOIC-20 packages, and compatibility with legacy FCT/F logic families.

Technical Context

The CY74FCT2245ATSOC implements a dual-rail 3-state transceiver architecture with independent transmit/receive (T/R) direction control and global output-enable (OE) gating. Its edge-rate control circuitry and on-die 25-Ω series termination resistors suppress transmission-line reflections without external components.

It supports partial-power-down operation via Ioff circuitry that disables outputs when VCC = 0 V, preventing backflow current during hot-insertion or mixed-voltage system power sequencing. Input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output drive (VOH ≥ 2.4 V at –15 mA, VOL ≤ 0.55 V at 12 mA) are fully TTL-compatible across –40°C to +85°C.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NIPDAU lead finish, MSL Level-1 (260°C reflow unlimited).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional transceiver applications.

Compared with CY74FCT2245ATSOC, the tape-and-reel variant offers identical performance with optimized manufacturing logistics, while the TSSOP alternative trades 1.45 mm height reduction for 10°C/W higher junction-to-ambient thermal resistance - critical for thermally dense test fixtures.

Availability

CY74FCT2245ATSOC is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive diagnostic interfaces, embedded legacy bus bridges, and automated test equipment requiring stable component supply and long-term lifecycle assurance.

Supply support for CY74FCT2245ATSOC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of industrial-grade reliability validation.

The CY74FCT2245ATSOC belongs to TI's FCT logic family, engineered for noise-immune, high-speed digital interfacing in harsh electromagnetic environments - particularly targeting industrial automation, test instrumentation, and automotive subsystems.

FAQ

What is the maximum operating frequency supported by CY74FCT2245ATSOC in a typical bus application?

The CY74FCT2245ATSOC has a maximum propagation delay of 4.6 ns, supporting reliable data transfer at effective bus clock rates up to approximately 217 MHz under ideal conditions. Real-world achievable frequency depends on trace length, loading, and termination - but the device is commonly used in 25–80 MHz synchronous bus interfaces with margin. CY74FCT2245ATSOC maintains timing integrity across its full –40°C to +85°C operating range.

Does CY74FCT2245ATSOC require external pull-up or pull-down resistors on control pins?

No. The CY74FCT2245ATSOC inputs (T/R and OE) have CMOS-compatible thresholds and do not require external biasing when driven by standard logic sources. However, per TI's recommended operating conditions, all unused inputs must be tied to VCC or GND to prevent floating states that could increase ICC or cause undefined output behavior. CY74FCT2245ATSOC does not include internal weak pull-ups or pull-downs.

Can CY74FCT2245ATSOC safely interface between 3.3-V and 5-V logic domains?

CY74FCT2245ATSOC accepts 3.3-V logic-high inputs (VIH min = 2.0 V) and outputs 5-V TTL-compatible levels, making it suitable for unidirectional 3.3-V → 5-V translation. However, it is not designed for bidirectional voltage translation: applying 5-V signals to A/B ports while VCC = 3.3 V violates absolute maximum ratings. For true bidirectional level shifting, a dedicated translator like TXB0108 is required. CY74FCT2245ATSOC operates strictly at 5 V.

What is the thermal performance of CY74FCT2245ATSOC in its SOIC-20 package?

The CY74FCT2245ATSOC in SOIC-20 (DW) package has a specified junction-to-ambient thermal resistance (θJA) of 58°C/W under standard JEDEC test conditions. With typical ICC of 0.2 mA static and dynamic supply current scaling linearly with switching activity, the device remains below 65°C junction temperature in most industrial PCB layouts with moderate copper pour. CY74FCT2245ATSOC's MSL Level-1 rating confirms unlimited floor life and 260°C reflow compatibility.

How does the Ioff feature of CY74FCT2245ATSOC protect the system during partial power-down?

The Ioff circuitry in CY74FCT2245ATSOC actively disables all outputs when VCC = 0 V, limiting leakage current to ±1 µA even if A or B port signals remain at valid logic levels (e.g., 3.3 V or 5 V). This prevents destructive backflow current through the device during hot-swap, power sequencing mismatches, or standby modes - a critical safeguard in modular backplanes and redundant power architectures. CY74FCT2245ATSOC maintains this protection across its full storage temperature range.